Wide Pitch Pre-split Blasting In The Construction Of Hydropower Stations In Sanbanxi Pilot Study

At present, the pre-splitting blasting with wide pitch of holes already obtained the experiment in the domestic and foreign large-scale mines, and has also yielded certain experimental results, moreover the pre-splitting blasting with big aperture, the width pitch of holes was a future development direction to practical application in the mine. In the water conservation and water electricity profession, the pre-splitting blasting which must carry on to protect the quality of side slope as technical measure, but as a result of its construction particularity, uses generally the pre-splitting blasting with small pitch of holes, the pre-splitting blasting with wide pitch of holes is short very much to obtain the experiment in the hydroelectric power station construction. Therefore it was necessary to conduct the experiment research of the pre-splitting with wide pitch of holes blasting in the water and electricity system.This article mainly studied the cracking mechanism of pre-splitting blasting with wide pitch of holes, the theoretical calculation of blasting parameter and the field test. First, by the theoretical analysis of the process of cracking mechanism of pre-splitting blasting based on the basic theories research outcomes of blasting mechanics, the elastics mechanics, fracture mechanics and rock mechanics, a basic calculation formula for the parameters of the pre-splitting blasting designing has been established. Then, based on some physical mechanics parameter of rock, the selection range of the parameters of the pre-splitting blasting in the project is obtained. Finally, the field test was carried on based on basic parameter of pre-splitting blasting which was selected. According to the analysis of special geological condition and the blasting effect, the pre-splitting blasting parameters applicable to the project weredecided. The best pre-splitting blasting effect were obtained by the reasonable pre-splitting blasting construction craft and parameters.The author did the experimental study to the pre-splitting blasting with wide pitch of holes which based on the pre-splitting blasting of BaYangHe materials yard of SanBanXi power station. First, the author designed four kind of different experimental plans according to the theory of the pre-splitting blasting. Then, the field test were carried on according to the designed proposal, and the research and the experiment of the key technologies as the drill hole, the powder charge structure and so on had been conducted. Finally, the economy, the social effect were used to appraise the pre-splitting blasting with wide pitch of holes. The successful experiments of pre-splitting blasting with wide pitch of holes, has written down a glory page in the water conservation and water electricity profession. It can be referred to use in similar the project.